Is my bf avoidant or losing feelings? 19F/20M

I 19F, have been seeing my bf 20M, for around 5 months, we were quite slow going into things, not rushing, he complimented me pretty often, we started being more vulnerable and saying when we missed one another and it was always reciprocated. Suddenly last few weeks or month, he started doing this less and less and started talking to me less even though before he was very chatty and always wanted to talk. He was super stressed and became depressed for a while after failing a big test about 2 weeks ago. He’s said he’s felt fine lately but still acting kinda funny, I asked him why he’s been acting different towards me but he doesn’t think he’s acting different. I’m a very anxious person and don’t know if it’s just me overthinking things or if there really is something.